Are you able to get another appointment with your PT to ask all those questions,
@cowgal? Write a list of everything you wish you'd asked and bring it to that appointment or to the next one you have with your OS or PA.
I had only one TKR, not a Bilateral, so the advice I got from my PT may not be applicable to you. I don't anticipate having the other knee done

::crossing fingers and toes::

. I used to contradance (some of the movements are like those in square dancing, but it's done in lines where couples move up and down the line and make cool patterns). There's a lot twirling on the right leg, but no jumping or stomping. I think the twirling contributed to the wear I experienced in my right knee. The physical therapist said contradancing would be OK with my new knee, but not swing or jitterbug. We also talked about various folk dances. No clogging, no Irish step dancing, no Scottish country dancing, no Russian sword dancing, nothing that has a lot of heel, toe, hop, hop, hop.
This is only an anecdote, but I know someone who had to have a new replacement put in because he was sitting on a wall that was not too high off the ground. He jumped down, landed wrong, and destroyed his TKR.
I was told by my ob/gyn that I am not at risk for osteoporosis because I'm overweight. My bones get a lot of strengthening exercise just through my everyday living. Do you know what your bone density is now, and how likely you are to develop osteoporosis? If you still really want to do a tandem jump at 70, you could always get an evaluation at age 68 or 69.
Glad your recovery appears to have avoided any more hiccups like those you had at the start.